In a number of exemplary applications utilizing electronic components, Metal Oxide Semiconductor (MOS) transistors are used as resistors. In such applications, a MOS transistor operating in linear region is used as a resistor. In the linear region of operation of the MOS transistor, by changing a gate voltage of the MOS transistor, resistance of the MOS transistor is changed. In the linear region, current through the MOS transistor may be represented by the equation:I=K×((VGS−Vth)×VDS−VDS2/2)  (1),where K is a proportionality constant, VGS is a voltage across the gate and source nodes of the MOS transistor, VDS is a voltage across the drain and source nodes of the MOS transistor, and Vth is a threshold voltage of the MOS transistor.
In many exemplary scenarios, there may be a signal swing present at one or more nodes, such as source or drain of the MOS transistor, which can cause distortion with respect to signal linearity of the MOS transistor. For example, if a signal swing Vd is present at the drain, the current in equation (1) may be represented by the equation:I=K×((VGS−Vth)×(VDS+Vd)−(VDS+Vd)2/2)  (2).The above equation (2) shows that the current has second harmonic (hereinafter referred to as ‘HD2’) distortion. In some exemplary scenarios, such distortion may be suppressed by providing an average of signal swings associated with the drain and source (for example, (Vd+Vs)/2, where Vd is the signal swing at the drain and Vs is the signal swing at the source) at the gate. In one exemplary scenario, in case of a single ended input (e.g., Vs is 0) and where the gate voltage is kept as (VG+Vd/2), the current through the MOS transistor becomes:I=K×((VGS−Vth)×(VDS+Vd)−(VDS+Vd)×VDS/2)  (3).It is noted that the current in equation (3) is linear, as it does not contain HD2 distortion. It is further noted that, though a number of exemplary circuits average the signals present at the source and drain and provide the averaged signal at the gate, however performing the averaging over a wide range of frequency may be a challenge when the gate voltage needs to be varied at a considerable rate in applications such as ultrasound receiver.